By Kathryn Doyle
(Reuters Health) - Several conditions that stem from a malfunctioning immune system – psoriasis, psoriatic arthritis and rheumatoid arthritis – may create a higher than average risk for heart-related problems and death, a new study finds.
“It’s not terribly surprising that there is an increased risk of heart disease because of the similar levels of systemic inflammation,” said co-lead author Dr. Alexis Ogdie of the rheumatology division in the Perelman School of Medicine at the University of Pennsylvania in Philadelphia.
Whole-body inflammation has also been linked to premature plaque buildup in the arteries, Ogdie told Reuters Health in an email.
The rough, red skin patches characteristic of psoriasis are caused by a chronic autoimmune disease affecting 7.5 million people in the U.S., according to the National Psoriasis Foundation, and can be treated with topical creams, ultraviolet light therapy or drugs.
Ten to 20 percent of people with psoriasis also develop a form of inflammatory arthritis associated with the disease, according to the Centers for Disease Control and Prevention.
Rheumatoid arthritis is a systemic inflammatory disease caused by the immune system as well. It affects more than 1 million U.S. adults, mostly women, according to the American College of Rheumatology.
“Psoriasis and rheumatoid arthritis have previously been linked to heart disease but there have been limited studies in psoriatic arthritis,” Ogdie said.
For the new study, Ogdie and her colleagues used primary care medical records in the UK to compare more than 138,000 adults with psoriasis, another 8,700 with both psoriasis and psoriatic arthritis and almost 42,000 people with rheumatoid arthritis to more than 81,000 other adults with none of the conditions.
The analysis followed all the subjects between 1994 and 2010.
More than half of those with rheumatoid arthritis or psoriatic arthritis had been prescribed a disease-modifying antirheumatic drug (DMARD) such as methotrexate, sulfasalazine or azathioprine, or a biologic DMARD like adalimumab.
Patients with any of the conditions were more likely to suffer a heart attack, cardiac arrest or stroke, or to die from one of those, over the 16-year period.
Those with psoriatic arthritis were 36 percent more likely than the comparison group to suffer a heart attack, regardless of whether they had been prescribed a DMARD.
A similarly heightened risk was seen among patients with severe psoriasis who had been prescribed a DMARD and those with rheumatoid arthritis who had not been prescribed a DMARD.
Those with rheumatoid arthritis who had been prescribed a DMARD had the greatest risk - almost twice that of people in the comparison group - of suffering a heart attack, according to the results in the Annals of the Rheumatic Diseases.
There was a comparable increase in risk for cardiovascular problems generally. Those with psoriasis who had not been prescribed a DMARD, and therefore probably had less severe disease, had the smallest increase in risk.
“Theoretically, treatment of the systemic inflammation and improvement of disease activity through the use of immunosuppressive medications should then decrease the development of atherosclerosis and the risk of heart disease,” Ogdie said.
But it’s very hard to make that judgment based on this kind of retrospective study, she said.
People with the most severe disease are also the most likely to be receiving rigorous treatment, she said, so it is hard to say whether the immune disease or the treatment is linked to their increased risk of heart disease.
The findings of increased risk are not new, said Dr. Dafna Gladman, who studies rheumatic diseases at the University of Toronto but was not involved in the analysis. What is new, she said, is the study looked at “a huge number of patients.”
However, the number of patients with psoriatic arthritis in the study seems quite low, said Gladman, since up to 30 percent of people with psoriasis also develop arthritis, and that may affect their results.
“A lot of people with psoriasis actually have arthritis even though doctors don’t recognize it,” Gladman told Reuters Health.
But that doesn’t detract from the results. In fact, the increased risk for people with psoriatic arthritis may be even higher than what they found here, she said.
This study and others have found moderate increases in heart risk, Ogdie said.
“Cardiovascular disease remains a leading cause of morbidity and mortality,” said Dr. Ole Ahlehoff of the Cardiology Department at The Heart Center at Copenhagen University Hospital Rigshospitalet in Denmark, who was not part of the new study.
“Patients with psoriasis, psoriatic arthritis, and rheumatoid arthritis should be educated that there is more to these conditions than skin and joint symptoms,” Ahlehoff said.
SOURCE: http://bmj.co/10wymPv Annals of Rheumatic Diseases, online October 28, 2014.